Evidence on the Carcinogenicity of C.I. Disperse …. Disperse Yellow 3 Uses Office of Environmental Health Hazard Assessment 3 • A textile dye for coloring nylon, polyvinyl chloride

Evidence on the Carcinogenicity of C.I. Disperse Yellow 3

January 25, 2013 Meeting of the Carcinogen Identification Committee

Cancer Toxicology and Epidemiology Section

Reproductive and Cancer Hazard Assessment Branch

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Identity of C.I. Disperse Yellow 3

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NN

OH

CH3

NH

O

CH3

CAS-RN: 2832-40-8

• Molecular Formula: C15H15N3O2

• Molecular Weight: 269.30 • Chemical Class: monoazo dye • Chemical Appearance: powder • Water Solubility: 1.18 mg/L (at 25°C)

C.I. Disperse Yellow 3 Uses

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• A textile dye for coloring nylon, polyvinyl chloride and acrylic fibers, wools, furs, cellulose acetate, polystyrene, and other thermoplastics

• Products include clothing, hosiery, and carpeting

• Dyes in ink products, and in pulp and paper manufacture

Occurrence of C.I. Disperse Yellow 3

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• Primarily used in dyeing of synthetic textiles such as yarns, fabrics, and carpets.

• Populations potentially exposed: – Workers in synthetic textile manufacturing

• Example: is one of 39 disperse dyes known to cause contact allergic dermatitis in textile workers.

– General public using synthetic textiles • Example: allergic eczema is associated with

nylon hosiery containing C.I. Disperse Yellow 3.

CI Disperse Yellow 3 at

various concentrations on

polyester fabric

Potential Exposures to C.I. Disperse Yellow 3 in Textile Manufacturing

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• Dyeing with C.I. Disperse Yellow 3 – Yarn stage

• Batch dyeing machines.

– Fabric/carpet stage • Continuous and batch dyeing machines.

• Handling of dyed yarns, fabrics, and carpets. – Exposure to CI DY3 (dermal and respiratory)

may be more likely in handling than in dyeing.

Carcinogenicity Studies in Humans

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• There are no epidemiology studies of humans with documented exposure to C.I. Disperse Yellow 3.

• There are four epidemiology studies of textile workers with potential exposure. – All four studies were of bladder cancer only. – All four were case-control design. – Three were conducted in Spain, one in New Zealand. – All four used interviewer-administered questionnaires to

collect exposure data – All four used standard occupation/industry coding. One

(Serra et al. 2008) additionally used detailed questions about the textile manufacturing workplace.

Epidemiology study: Gonzales et al., 1988

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• Case-control study in Spain. – Incident cases from one hospital. – Deceased cases from a local death registry.

• 57 bladder cancer cases identified 1978 -1981. • 107 hospital and deceased controls • “Textile dyeing or printing” OR=4.41, 95% CI= 1.15-16.84,

based on 8 exposed cases and 3 exposed controls. • C.I. Disperse Yellow 3 was among 72 dyes mentioned in

article. • Limitation: most subjects deceased (75%) by time of

interview, requiring proxy interview (e.g. with spouse).

Epidemiology study: Gonzales et al., 1989

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• Case-control study in Spain – Incident cases from 12 hospitals in four geographic regions.

• 497 bladder cancer cases (438 male & 59 female) occurred 1985 -1986.

• Two control groups – Hospital – General population.

• “Textile dyers” OR=1.29, 95% CI= 0.5-3.1, based on 11 exposed cases and 17 exposed controls.

• C.I. Disperse Yellow 3 was not mentioned in the article.

Epidemiology study: Dryson et al., 2008

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• Case-control study in New Zealand – Cases from nationwide cancer registry.

• 213 bladder cancer cases occurring 2003 -2004. • 471 controls from general population. • “Textile products machine operators - textile bleaching,

dyeing, and cleaning” OR=0.81, 95% CI=0.19-3.54, based on three exposed cases and 10 exposed controls).

• C.I. Disperse Yellow 3 was not mentioned in the article.

Epidemiology study: Serra et al., 2008

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• Case-control design at 18 hospitals in Spain. • 1,182 bladder cancers (1,065 male, 117 female) 1998-2001. • 1,221 controls from the same hospitals. • Interviewer-administered questionnaires with module

designed specifically for textile industry. • “Winding, warping, and sizing” with “synthetic” materials

(OR=15.39, 95% CI=1.89-125.29, based on 11 exposed cases and 1 exposed control).

• “Synthetic” materials 10+ years (OR=2.62, 95% CI 1.14-6.01, based on 21 exposed cases and 9 exposed controls)

• C.I. Disperse Yellow 3 was not mentioned in the article.

• National Toxicology Program (NTP), 1982 • F344 rats (males, females) - 50 animals/sex/dose - 0, 5,000 or 10,000 ppm in feed for 103 weeks and terminated by 104 weeks. • Liver and stomach tumors were observed in males

Two Carcinogenicity Studies in Rats

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Organ Tumor Dose group (ppm) Trend

test p value 0 5000 10000

Liver

Hepatocellular adenoma 1/31 15/45** 10/39* <0.05

Combined hepatocellular adenoma and carcinoma

2/31 15/45** 11/39* <0.05

Stomach

Glandular portion: Combined adenoma, mucinous adenocarcinoma, and sarcoma

0/30 2/45 1/39 NS

Non-glandular portion: Combined squamous cell papilloma and fibrosarcoma

0/30 2/45 0/39 NS

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Feed Studies in Male F344 Rats

Pairwise comparison with controls; * p<0.05, ** p<0.01

Feed Studies in Female F344 Rats

• No treatment-related tumors were observed

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• National Toxicology Program (NTP), 1982 • B6C3F1 mice (males, females) - 50 animals/sex/dose - 0, 2,500 or 5,000 ppm in feed for 103 weeks and terminated by 104 weeks. • Lung tumors in males. • Hematopoietic system and liver tumors in

females.

Two Carcinogenicity Studies in Mice

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Feed Studies in Male B6C3F1 Mice

Pairwise comparison with controls; * p<0.05, # p=0.055

Organ Tumor Dose group (ppm) Trend

test p value 0 2500 5000

Lung

Alveolar/bronchiolar adenoma 2/47 6/42 9/46* < 0.05

Combined alveolar/bronchiolar adenoma and carcinoma

3/47 7/42 9/46# < 0.05

Pairwise comparison with controls; * p<0.05, ** p<0.01 16

Feed Studies in Female B6C3F1 Mice

Organ Tumor Dose group (ppm) Trend test

p value 0 2500 5000

Hemato-poietic System

Malignant lymphoma 10/50 16/50 19/50* < 0.05

Combined malignant lymphoma and leukemia

10/50 17/50 20/50* <0.05

Liver

Hepatocellular adenoma 0/50 6/47* 12/46** <0.001

Hepatocellular carcinoma 2/50 4/47 5/46 NS

Combined hepatocellular adenoma and carcinoma

2/50 10/47* 17/46** <0.001

Genotoxicity in Non-mammalian Species

•Salmonella reverse mutations - Positive: TA 97, 98, 1537, 1538 strains (+/-S9), and

100 (+S9) strains - Negative: TA 100 (-S9) and 1535 (+/-S9) strains •Chromosomal aberrations in Frog larvae - Positive •Sex-linked recessive lethal mutations in Drosophila - Negative

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In Vitro Genotoxicity in Mammalian Species

• Mouse lymphoma forward mutations - Positive: 2 tests (+S9) - Negative: 3 tests (-S9)

• Sister chromatid exchange in CHO cells - Positive: 1 test (+S9), 1 test (-S9) - Negative: 1test (-S9)

• Chromosomal Aberrations in CHO cells - Negative (+/-S9)

• Unscheduled DNA synthesis in rat hepatocytes - Positive (-S9)

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In Vivo Genotoxicity in Mammalian Species Negative

• Micronucleus induction in mouse bone marrow

• DNA damage in rat liver

In Vitro Cell Transformation Negative

• BALB/c 3T3 mouse cells (-S9)

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Pharmacokinetics and Metabolism

• Absorption – Dermal absorption is expected – Oral absorption is inferred – Inhalation unknown

• Azoreduction – Azo dyes undergo reductive cleavage of the azo

bond and form aromatic amine metabolites – Metabolites: 4-Aminoacetanilide and 2-Amino-

p-cresol

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Proposed Mechanism Of Azo Reduction

Adapted from Levine (1991)

C.I. Disperse Yellow 3 and its Expected Metabolites

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C.I. Disperse Yellow 3

Genotoxicity of Metabolites

Chemical Genotoxicity

In vitro In vivo

4-Aminoacetanilide Salmonella reverse mutation

Mouse bone marrow; chromosomal aberrations

2-Amino-p-cresol

Salmonella reverse mutation; mouse lymphoma forward mutation

Not tested

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Structurally Related Chemicals

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C.I. Disperse Yellow 3 Azobenzene

Prop 65 listed IARC 3

p-Aminoazobenzene

NN

OH

CH3

NH

O

CH3

NN

NN

H2N

o-Aminoazotoluene

Prop 65 listed IARC 2B

Oil Orange SS

Prop 65 listed IARC 2B

NN

NH2

CH3

CH3

NN

OH

CH3

Prop 65 listed IARC 2B

Structurally Related Chemicals

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C.I. Disperse Yellow 3 4-Aminoacetanilide 2-Amino-p-cresol

NN

OH

CH3

NH

O

CH3

2,4-Diaminotoluene

Prop 65 listed IARC 2B

2-Aminotoluene

Prop 65 listed IARC 1

Phenacetin

Prop 65 listed IARC 2A

NH2

NH

O

CH3

H3C NH2

OH

CH3

H2N NH2

CH3

NH2

CH3O

NH

H3C

O

Carcinogenicity of Structurally Related Chemicals

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Chemical Liver Other Sites

Mice Rats Mice Rats

C.I. Disperse Yellow 3 F M

F (hematopoietic system)

M (lung) M (Stomach)

Azobenzene M M (spleen)

p-Aminoazobenzene M M M (skin)

o-Aminoazotoluene MF MF MF (lung)

F (soft tissues) MF (lung)

Oil Orange SS MF (bladder)

M (intestinal)

2,4-Diaminotoluene F MF M (kidney, skin)

F (mammary, lymphoma)

2-Aminotoluene F MF (blood vessels)

M (abdominal, scrotum, skin, spleen)

F (mammary, bladder, spleen)

Phenacetin M(urinary tract) MF (urinary tract, nasal cavity)

Possible Mechanisms of Action

• Genotoxicity - Mutagenicity and clastogenicity by the

parent compound and metabolites - Structural similarity with carcinogenic

monoazo compounds and related aromatic amines that are genotoxic

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Summary of Human Evidence

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• Four case-control studies of bladder cancer risk among textile workers.

• Exposure-related limitations of all four studies: – C.I. Disperse Yellow 3 was just one of many disperse

dyes used. C.I. DY3 was mentioned in only one study. – No exposure measures or cancer risk results for

specific dyes. • Two of the four reported significant associations for jobs

with potential exposure to C.I. Disperse Yellow 3. • The studies are inadequate to assess the relationship

between C.I. Disperse Yellow 3 exposure and cancer risk.

F344 rats

•Males: - Benign and combined malignant / benign liver tumors -Rare stomach tumors

•Females: -No treatment-related tumors

Summary Of Animal Evidence

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B6C3F1 mice

•Males: - Benign and combined malignant/benign lung tumors •Females: - Hematopoietic system tumors

- Benign and combined malignant / benign liver tumors

Summary Of Other Relevant Evidence

• In vitro genotoxicity in a variety of systems • Metabolism to genotoxic metabolites • Structurally similar to other carcinogens

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